Farpoint FP401 Bahtinov Focus Mask for 3.5-in to 6.5-in
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Farpoint FP401 Bahtinov Focus Mask for Telescopes with Dew Shield or Front End Diameter from 3.5" to 6.5"

SKU: FARFP401

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Questions & Answers

Kathleen S : Will this work with my 102" orion mak telescope?James A : I believe you mean to say your '102mm' orion mak telescope, not a 102" one. 102mm equates to a 4 inch aperature. I can use this same Bahtinov mask with my 4 inch refractor and with my 6 inch reflector. It has sliding plastic set screws that you adust to "grab" the outside edge of the front of the telescope thereby covering the aperature with the mask. As the description says these set screws can be adjusted to support front lenses 3.5 to 6.5 inches in diameter. The trick is to ensure all set screws are equal distance in their slots so the mask is perfectly centered on the scope. That permits the mask to do its job properly.JOSEPH C : yes
John S : What kind of material is this mask made from (i.e. aluminum, plastic, etc.)?TONY A : It's a tough plastic. It's not going to pose any risk of scratching paint finishes.IAN T : this item is made of plasticEDWARD M : PlasticOBIN R : I's a very durable plastic that is also lightweight.ROBERT H. B : It's plastic. about 1/8" thick. It plenty strong enough. I use it on 8" Orion Starquest reflector and a 102 mm Explore Scientific refractorSTEVE W : Plastic.FRANK P : This Bahtinov mask is made of a heavy-grade plastic, rigid, yet flexible and textured on one side, with rubber grommets and plastic pinch bolts for fastening to the scope. It's precise, well-made, and should last indefinitely. FrankGREG W : Plastic, so light weight, oblivious to moisture, won't scratch telescope, etc. Really works to help focus telescope.GALE D : PlasticEDWARD D : It is made of plastic. It is about 3/32" thick, and reasonably flexible.MITCH R : It's plasticJOHN S : According to Fairpoint's website, the masks are made from ABS plastic.
David M : I'm looking at the FP401 Bathinov focus mask. Will this work on my Meade EXT125 Schmidt Cassegrain telescope?SCOTT B : Yes. It has 3 plastic posts that adjust to the correct diameter to allow it to slide onto the front of the optical tube. It's a loose fit but works fine.DAVID M : I purchased the FP401 for my old nexstar 5 scope. I place it over the celestron 5 inch lens shade/dew shield and there is plenty of adjustment left. PS I remounted the scope on a Celestron CG5 mount and I'm starting imaging.CHARLES C : Yes...easily. I just tried it. Chuck/divenutsEUGENE B : It works very well on my 130mm Newtonian reflector (tube O.D. 6") and my 90mm Sky Watcher Mak (tube O.D. 4"). Screws are attached to rubber grommets on the mask which you position to fit your telescope tube (adjustable from 3.5 to 6.5"), so it should easily fit your scope. There are types that have a central hole to fit around the secondary mirror holder on Schmidt Cassegrains, but personally I don't think I would want anything touching the corrector plate.DAVID B : Hi David M, Yes it should work on your ETX125. According to one source the tube diameter is 146mm (~5.7"), this is within the 3.5 to 6.5" range of the FP401. The attachment mechanism is very simple (and not very secure). It is simply three plastic thumbscrews held into the slots with rubber grommets. To mount it to your scope you simply push the screws inward in the slots and they gently press against and grip the outer diameter of the tube. It is not a very secure mounting mechanism, but it is very adjustable. This mask is very lightweight so it works. Also, it makes it very quick to remove it once you have the focus set.ROBERT W : I can't tell you for sure about working with a Schmidt-Cass but it works great with my 4-inch refractor

Reviews about this item

Review Summary

2022-05-17T08:27:27

Rated 5 out of 5

Bahtinov Focus Mask

Great tool to focus my telescope and CMOS camera

Orlando M.

2021-07-14T08:17:41

Rated 5 out of 5

A very good product

Does what it says it does, helps with fine focusing for astrophotography.

ERIK M.

2020-06-23T10:16:45

Rated 5 out of 5

Must need for perfect focus

Does just as it says

KELLY M.

2017-06-06T11:00:17

Rated 5 out of 5

Sure focus

Very easy to use. Fits my 130mm Newtonian well.

WILLIAM C.

2016-09-08T11:33:33

Rated 5 out of 5

great focusing aid for refractors

this is a must for accurate focusing on stars. live view helps, but the bathinov mask will get you in sharp focus every time.

ALIN T.

2016-07-04T09:35:09

Rated 5 out of 5

gave best focus I've ever had

Easy to use. Quick. Focuses camera the most crisp I've ever had. Will use from now on.

BROOK R.

2014-04-07T21:00:00

Rated 4 out of 5

good deal

works great

willyr

2014-02-11T19:00:00

Rated 5 out of 5

Farpoint FP401 Bahtinov mask

Needed a focusing mask for my WO 110 ED for DSLR imaging. This product worked perfectly, and the price shipped was a pleasant surprise. Highly recommended!

Astronomicus

2013-08-05T21:00:00

Rated 5 out of 5

Bahtinov Focus Mask

Excellent . Work great.

Astro S.

2013-07-21T21:00:00

Rated 5 out of 5

Essential! It will pay for itself fast!

I remember one night I spent four hours trying to get a great photo of a nebula. Through the camera viewfinder it looked like everything was in sharp focus. After coming back inside it turns out that the camera slid slightly in the focuser. It slid just enough to render about 3 hours of time totally wasted! The Farpoint Bahtinov mask is a great way to check your focus and check to make sure your camera did not slip. The time you save will make it well worth the cost. HIGHLY recommended!

Obin R.

2013-07-08T21:00:00

Rated 5 out of 5

Bahtinov Focus Mask for Telescopes

There's no reason to spend more as this mask is well made and durable.

fpirrone

2013-04-01T21:00:00

Rated 5 out of 5

Must have for photography!

I use this on an astro-tech 6" Ritchey-Chretien and an astro tech 6" imaging newtonian. This makes it easy (and the cheapest of all the possible ways) to achieve tack-sharp focus.

DANIEL K.

About Farpoint FP401

FEATURED REVIEWS

Sure focus

By WILLIAM C.

Very easy to use. Fits my 130mm Newtonian well.

great focusing aid for refractors

By ALIN T.

this is a must for accurate focusing on stars. live view helps, but the bathinov mask will get you in sharp focus every time.

Bahtinov Focus Masks...
• In 2008 an amateur telescope maker and astronomer ppublished an ingenious new way to easily focus your DSLR, webcam or CCD camera for taking astrophotos. The method is simple, very intuitive and the device has universally been named after the inventor. The Bahtinov Mask.

• Farpoint manufactures this *LIFESAVING* astrophotography tool out of virtually indestructable ABS plastic and comes in two major types and in a range of sizes.

• One mask is a general purpose mask designed to fit refractors and newtonian telescope. The other mask is designed to fit Schmidt Cassegrain telescopes. Both types of mask are available in a range of sizes to cover your needs.

Farpoint FP401 Features

  • Bahtinov focus mask for small to medium telescopes
  • Fits telescopes with dew shield or tube diameter from 3.5" to 6.5" diameter

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Key Features

  • Fits telescopes